import numpy as np
arr = np.arange(4)
print('一维数组arr:\n',arr)
arr1 = np.arange(1,10,2)
print('一维数组arr1:\n',arr1)
arr2 = np.arange(0,1,0.2)
print('一维数组arr2:\n',arr2)
arr3 = np.arange(5,0,-1)
print('一维数组arr3:\n',arr3)

arr4 = np.linspace(2,8,60,endpoint=False,retstep=True)
print(arr4)